1. Field of the Invention
This invention relates to a method and apparatus for automating all the steps of a process for laundering and finishing dirty rectangular sheets of fabric at a plant such as the laundry.
2. Background Art
Heretofore at the laundry, it has been customary to receive a heap of dirty rectangular sheets of fabric, deprive the sheets of dirt at a laundering step for laundering or cleaning the sheets collectively with water or a detergent, then introduce the laundered or cleaned sheets into a dewatering step to dewater the sheets with a dewatering device, subsequently convey the dewatered sheets to a drying and disentangling step to dry the moist sheets and, at the same time, disentangle the sheets which have been entangled into a crumpled mass, and heap the sheets which have been disentangled. For the purpose of extracting one of the sheets from the heap and ironing it, this sheet must be supplied to an ironing device as held in a spread state with the opposite edges (sides) thereof neatly parallelled.
It has been further customary, therefore, to spread manually the sheets which have been disentangled, supply the spread sheets to an edge parallelling step and, with the aid of an edge parallelizing device, parallel the edges to the device, introduce the sheets with the parallelled edges into an ironing step and subject them to a finish ironing, fold the finish ironed sheets at a folding step, wrap the folded sheets at a wrapping step, and put the wrapped sheets to temporary storage prior to delivery.
For laundering and finishing the sheets of fabric, these sheets are required to undergo the steps mentioned above. In the conventional process for finishing laundered rectangular sheets of fabric, the laundering, dewatering, drying, disentangling, edge parallelling, ironing, folding, wrapping, and storing steps have been already mechanized and have been performed by the use of relevant devices without requiring any manual work. The step for spreading sheets between the drying and disentangling step and the edge parallelling step or the ironing step, however, has defied mechanization because the sheets by nature are supple and liable to collapse. At this step, therefore, several employees are engaged to perform the works of extracting individual sheets one by one from the heap, disentangling them, seeking out one corner of each sheet and the edge of the sheet extending from this corner or the corner of the sheet adjacent thereto, taking firm hold thereof, spreading the relevant sheets, and supplying the spread sheets to the edge parallelling device or the ironing device at the subsequent step.
Since these works compel the employees to bear the pain of hard labor under the adverse environment of high temperature and high humidity, they suffer from poor operational efficiency and boost the cost of operation. Since the spreading step which forms part of the whole process of laundry relies on such manual works, the whole process of laundering dirty sheets of fabric and finishing the laundered sheets cannot be automated. This fact poses the problem of interrupting any attempt at realizing an unattended operation of the laundry under an adverse environment.
This invention has an object of realizing unattended operation of the laundry as a plant and automation of the whole process of a series of steps for laundering dirty sheets of fabric and finishing the laundered sheets by providing a method and apparatus for the work of spreading sheets of fabric at one step in a series of steps ranging from laundering dirty sheets through finishing laundered sheets, namely the step for taking firm grip of one sheet out of a heap of sheets, suspending the sheet, spreading this sheet, and supplying the spread sheet to a device at the next step.
For accomplishing the object mentioned above, such concrete spreading means as will be cited herein below are provided for the spreading step which comprises picking up one of a heap of sheets of fabric which have been laundered, dewatered, dried, and disentangled, taking firm grip of one arbitrary corner part of the sheet together with the point (portion) of the sheet terminating an arbitrary width of one edge thereof extending from the one corner or another corner part adjacent across the edge to the one corner.
A first chuck (a sheet gripping member) which is vertically reciprocated by and along an elevating column takes firm grip of one of the heap of rectangular sheets of fabric. When the first chuck is moved upward along the elevating column to suspend the sheet, the sheet hangs down under its own weight. So long as the sheet is not entangled, the corner part of the sheet separated by the largest distance from the point of grip (the corner itself or the portion near the corner) assumes the position of the lowermost end of the suspended sheet. The sheet is placed in a device adjoining the elevating column and serving to extract the corner part of the sheet. A second chuck then takes firm grip of the one corner part of the sheet located at the lowermost end thereof and the first chuck looses the sheet.
The sheet hangs down under its own weight from the second chuck and, as a result, the lowermost end thereof constitutes itself the corner part which is diagonal to the corner part already gripped by the second chuck. The device for extracting the corner part of the sheet extracts the diagonal corner part and a third chuck takes firm grip of this diagonal corner part. When the second and the third chuck are laterally moved in the horizontal direction to stretch the sheet, the sheet is folded along the diagonal line connecting the corner parts gripped by the second and the third chuck and caused to hang down in the shape of an inverted triangle. From this state, the sheet is supplied to each of the first through the fifth spreading means to be described below.
In the first means for spreading a rectangular sheet of fabric, the second and the third chuck are caused to take firm grip of one corner of the sheet and the corner diagonal thereto and hang the sheet down in the shape of an inverted triangle, then the second and the third chuck are moved onto a rectangular mounting stand so as to lay the sheet folded in the shape of an inverted triangle on the mounting stand, and the second and the third chuck are moved on the mounting stand so as to drag the sheet thereon. A fulcral post for inhibiting the movement of the sheet is disposed on the central line of the mounting stand so that the second and the third chuck may be parallelly moved in the areas on the mounting stand divided by the central line.
At the same time that the folding edge of the sheet collides against the fulcral post, one of the two chucks is caused to looses the sheet and the other chuck alone is left continuously dragging the sheet. During the continued movement of the sheet, the fulcral post imparts on the sheet a gathering action such that the sheet may advance toward a line sensor which is disposed across the paths for travel of the chucks extending parallelly to the central line on the mounting stand. When the line sensor detects one edge of the sheet, the movement of the chucks or the movement of the sheet is stopped.
Thereafter, the chuck still keeping grip of the sheet is caused to loose the sheet. Another chuck which is adapted to move in the direction perpendicular to the central line on the mounting stand takes firm grip of one corner part of the sheet together with the point of the sheet terminating an arbitrary width of one edge thereof extending from the one corner and suspends and spreads the sheet.
In the second means for spreading a rectangular sheet of fabric, the second and the third chuck take firm grip of one corner part of the sheet together with another corner part thereof diagonal to the one corner part, fold the sheet in the shape of an inverted triangle, open the doubled parts of the folded and suspended sheet and straighten the folding edge. A rotary arm is rotated and approximated in the direction of the edge of the sheet. Another chuck adapted to slide on the rotary arm takes firm grip of one corner of the sheet together with a point of the sheet terminating an arbitrary width of one edge thereof extending from the one corner.
The rotary arm is attached to rotary shafts which are disposed near members for gripping the mutually diagonal corner parts of the sheet and connected to a servo motor which is set rotating by a command from a control device adapted to effect necessary control in response to a signal from a sensor for detecting the position of the edge of the sheet. The rotary arm is meshed with a toothed wheel, a clutch, a universal joint, etc. so as to produce a three-dimensional rotation both vertically and laterally. The chuck which is slidable on the rotary arm is so constructed that the positions at which the chuck takes firm grip of the sheet are suitably determined by the movement of itself proportionate to the size of the edge of the sheet.
When the edge of the sheet is gripped and the mutually diagonal corners of the sheet are loosed, the chuck of the rotary arm takes firm grip of the corner of the rectangular sheet of fabric together with the point of the sheet terminating an arbitrary width of one edge thereof extending from the one corner and suspends and spreads the sheet.
In the third means for spreading a rectangular sheet of fabric, longitudinal rails are disposed on the mounting stand as extended in the longitudinal direction along the opposite lateral edges of the upper side of the mounting stand, lateral rails are disposed so as to be moved on the left longitudinal rail and extended in the lateral direction, and a left chuck adapted to take firm grip of one corner part of the sheet together with the neighborhood of the corner part diagonal to the one corner is disposed so as to be moved in the lateral direction on the lateral rails and to be moved longitudinally and laterally on the mounting stand in response to the movement of the lateral rails in the longitudinal direction on the left longitudinal rail. A right chuck adapted to take firm grip of one corner part of the sheet is disposed so as to be quickly moved longitudinally on the right longitudinal rail. The left chuck and the right chuck are interconnected through the medium of a telescopic link bar.
A sensor for discerning the fact that the edge of the sheet has been straightened is disposed on the mounting stand below the right longitudinal rail. A sensor for implementing the operation of the left and the right chuck and a control device therefor are disposed. A chuck which is adapted to take firm grip of one corner of the sheet together with a point of the sheet terminating an arbitrary width of an edge extending from the corner and then move the sheet is provided and operated to spread the sheet.
In the fourth means for spreading a rectangular sheet of fabric, the second and the third chuck take firm grip of one corner of the sheet together with another corner diagonal to the one corner, suspend the sheet in the shape of an inverted triangle, and then move the suspended sheet to above the front side of the mounting stand disposed inside a base stand. The second and the third chuck are attached to a bridge member which is disposed astride the left and the right longitudinal rail laid along the upper lateral edges of the base stand as extended in the longitudinal direction. The bridge member is attached to a drive device formed of such transmitting means as a chain or a belt passed round such rotary means as a sprocket or a wheel disposed on the shaft of a motor and is consequently enabled to be moved by the rotation of the motor on the longitudinal rails in the longitudinal direction of the base stand.
The mounting stand is provided near the middle thereof with lateral rails laid laterally across the mounting stand and is also provided with a fourth chuck adapted to move on the lateral rails and a sensor adapted to detect the edge of the sheet on the lateral rails. It is further provided with a control device for controlling the movement of the chuck in response to a signal from the sensor. The fourth chuck takes firm grip of one corner of the sheet diagonal to the one corner of the sheet mentioned above and suspends and spreads the sheet.
In the fifth means for spreading a rectangular sheet of fabric, the second and the third chuck take firm grip of one corner of the sheet together with another corner diagonal to the one corner, suspend the sheet in the shape of an inverted triangle, then open the skirt of the suspended rectangular sheet and take firm grip of one part of an arbitrary side (edge) of the sheet, and loose the corner part on the gripped part side to hang the rectangular sheet of fabric down. The chucks move the sheet in the ensuant state to a pair of laterally symmetric mounting stands adapted to move in the lateral direction and disposed flush with each other. This fifth means is provided with a sensor adapted to discern the fact that the lower edge of the suspended sheet has been straightened. The chucks loose the sheet at the time that the sensor discerns the fact that the lower edge of the sheet has been straightened on the mounting stands.
The opposite lateral edges of the sheet mounted on the left and the right mounting stand are severally moved toward the centers of the mounting stands by the movement of the mounting stands each formed of a belt conveyor or roller. Corner sensors for detecting the opposite corners of the lower edge of the sheet are disposed at an equal distance from the centers of the left and the right mounting stand. The left and the right mounting stand are made to stop their movement when the opposite corners of the lower edge of the sheet are detected by the corner sensors. The chucks take firm grip of the opposite corners of the sheet separated by an equal distance from the centers of the mounting stands and suspend and spread the sheet.
Owing to the means for spreading the sheet described above, this invention automates continuous operation of a series of steps comprising a step for placing a multiplicity of dirty rectangular sheets of fabric in a washing machine and washing them therein, a step for dewatering the laundered sheets, a step for drying and disentangling the moist sheets, a step for taking firm grip of one of the heap of sheets and spreading the sheet, a step for straightening one edge of the spread sheet parallelly to the axis of the apparatus, a step for ironing the sheet, a step for folding the sheet, and a step for wrapping the folded sheet and putting the wrapped sheet to temporary storage in all possible selected sequences or combinations.
Owing to the constructions described above, the means for spreading the sheet mentioned above fulfill the following functions.
The first means for spreading a rectangular sheet of fabric takes firm grip of mutually diagonal corner parts of the rectangular sheet and spreads the sheet in the lateral direction, folds the sheet along the diagonal line as an edge, hangs the folded sheet down from the edge, lays the suspended sheet on a mounting stand, and drags the sheet as laid thereon. It then moves the chucks so as to inhibit the advance of the middle point of the edge of the sheet from the ensuant state, loose the grip of the sheet on one side thereof, and drag the sheet by the grip of the corner on the other side.
Since the part of the sheet on the farther side from the middle point, therefore, is inhibited from advancing by the fulcral post disposed as a movement inhibiting member at the middle point, the sheet is moved around the fulcral post as though it were slid thereon from the one side to the other side. As a result, the part of the sheet on the one side in effect is pushed from behind by the part of the sheet on the other side and the whole of the sheet is slid askew as dragged by dint of the entanglement of the corner parts. The one edge on the one side of the sheet, therefore, is moved as turned on the mounting stand around the entanglement of the corner parts and then parallelled to the center line of the mounting stand.
After the edge of the sheet has been parallelled to the center line, the chucks are driven out in the lateral direction perpendicular to the center line and caused to take firm grip of the edge. Since the chucks consequently take firm grip of the edge evenly at the corner part and the point terminating an arbitrary width of an edge extending from the corner, the center of gravity of the sheet falls on the side on which the point on the edge is gripped. The edge suspended from the gripped corner part hangs down vertically under its own weight and the sheet is consequently spread.
The second means for spreading a rectangular sheet of fabric is provided with a rotary arm incorporating therein a chuck and having the center of rotation thereof on an extension of the diagonal line of the rectangular sheet of fabric the mutually diagonal corner parts of which are gripped by the chuck. The means takes firm grip of the diagonal corner parts of the sheet, suspends the sheet in the shape of an inverted triangle, opens the skirt of the suspended sheet, relieves the sheet of the folded state, sets the rotary arm rotating along the inclination of an arbitrary edge of the sheet, and causes the chuck attached to the rotary arm to take firm grip of a corner of the sheet and a point terminating an arbitrary width of an edge extending from the corner and suspend the sheet. Since the center of gravity of the sheet consequently falls below the arbitrary point on the edge, the weight solely of the edge hanging down from the gripped corner is exerted on the edge. The suspended edge, therefore, is straightened vertically and the sheet is spread.
The third means for spreading a rectangular sheet of fabric causes the right chuck adapted to move in the longitudinal direction on the mounting stand to renew the grip of one corner part of the sheet which has been gripped thence by the second chuck and the left chuck adapted to move in both the lateral direction and the longitudinal direction of the mounting stand to renew the grip of the neighborhood of another corner part diagonal to the one corner part of the sheet which has been gripped thence by the third chuck. Thereafter, it moves the right chuck rapidly toward the rear side of the mounting stand and, at the same time, moves the left chuck slowly toward the rear side and simultaneously toward the right. As a result, the whole sheet is spread in the shape of a triangle and laid on the surface of the mounting stand, slid horizontally toward the right, rotated around the right chuck as the center, and moved toward the rear side.
When, in consequence of this rotation, one edge of the sheet is likewise rotated about the right chuck as the center and the straight line of the one edge of the sheet is parallelled to the line of movement of the right chuck, namely the right longitudinal rail, the sensor discerns this fact and the two chucks are moved in the directions perpendicular to the lateral edge of the mounting stand and then caused to take firm grip of a corner part of the sheet and a point terminating an arbitrary width of an edge extending from the corner, suspend the sheet, and spread the sheet.
The fourth means for spreading a rectangular sheet of fabric causes the second and the third chuck to take firm grip of mutually diagonal corner parts of the sheet and then moves the second chuck toward the right to stretch the sheet. The sheet is folded along the diagonal line connecting the gripped corners as the edge, spread in the shape of an inverted triangle, and suspended. With the sheet in the ensuant state, the second and the third chuck are moved onto the mounting stand disposed in the front part of the interior of the framework of the base stand and moved continuously on the mounting stand so as to lay the sheet thereon.
While the sheet is in the process of moving on the mounting stand, the third chuck looses the grip and the second chuck still holding firm grip on the sheet is moved on the mounting standing so as to drag the sheet therein. When the corner part of the sheet adjacent to the corner part of the sheet still gripped by the second chuck crosses a groove serving as a path for movement of a fourth chuck, the sensor discerns this fact, consequently causes the second chuck to stop its movement and the fourth chuck to move toward the right and take firm grip of the corner part, and then causes the second and the fourth chuck to move toward the left and consequently take firm grip of one corner of the sheet and another corner diagonal to the one corner, suspend the sheet outside the mounting stand, and spread it.
The fifth means for spreading a rectangular sheet of fabric takes firm grip of an arbitrary edge of the sheet at the positions separated by an equal distance from the two corners sharing the edge. The gripped positions of the sheet are based on the idea that they are equidistant from the center of the edge mentioned above. In implementing this idea, the sheet is spread and laid fast on the mounting stand so as not to be fluttered. The sheet is placed evenly relative to the laterally opposite ends thereof on the mounting stand so that the opposite corners of the arbitrary edge of the sheet may be equidistant from the center of the mounting stand. This sheet is rolled in toward the center of the mounting stand so as to drag the left and the right corner toward each other.
When the left and the right corners of the edge of the sheet are brought to an equal distance from the center of the mounting stand, the left and the right chuck moving parallelly to each other at an equal distance from the center of the mounting stand take firm grip of the corner parts of the sheet and suspend the sheet. As a result, the left and the right chuck take firm grip of one corner part of the sheet together with another corner part thereof adjacent to the one corner part at the positions which are equidistant from the center of one edge of the sheet and then spread the sheet. The sheet, therefore, can be placed with the edge thereof aligned with the axial line of the apparatus.